The present invention relates to the field of retaining clamps and more particularly to what is referred in the industry as tube alignment bars which are utilized to clamp a series of tubes in parallel with each other.
Steam boilers used for heating utilize a series of boiler tubes which are generally exposed and vertically hang downward from the ceiling of a building structure and swing free in this position. These tubes are referred to in the industry as secondary super heater or reheat tubes, or heat recovery tubes for recovering lost heat. These boiler tubes must be aligned and held in position in parallel.
The presently known procedure for clamping these boiler tubes together in parallel incorporates a tube alignment bar which consists of two elongated parallel bar halves for clamping a series of these tubes in parallel therebetween such that the tubes are then running perpendicular to the bar halves. These bar halves each have a series of recesses which oppose each other when the two bar halves are aligned in parallel to thereby in combination provide a series of split ring openings when the bar halves are clamped together to receive the tubes in parallel alignment.
Alignment protrusions extend from each of bar half toward the other between each recess. Opposing alignment openings are provided between each recess on the other bar half to receive the respective alignment protrusions therethrough so that when the bars are clamped together in parallel engagement the protrusions extending from each bar half are guided through the opposed alignment openings in the other bar half so that when the clamping bars are fully engaged they form a series of rings for aligning and retaining the tubes therein in a parallel series.
The problem with these preexisting tube alignment bars is that the boiler tubes to be aligned and clamped in parallel are found in a relatively haphazzard nonaligned array. Accordingly, to even initially fit the tube alignment bars over a section of the series of boiler tubers one first has to provide an independent clamp which is screwed or otherwise clamped down on opposite sides of the tubes to be aligned to clamp the boiler tubes. The tubes are then adjusted in this clamp until they are properly spaced in parallel alignment with each other and the clamp is further secured to hold them in position. Only then can one initially apply the prior art alignment bar.
The tube alignment bar is provided or laid over the parallel prealigned tubes adjacent the clamp, clamped together, and the parallel bar halves thereof are then welded together to retain the tubes in their parallel alignment. Thereafter the initial alignment clamp and the clamp on the bar halves can then be removed and the process is again repeated.
The requirement of having to utilize these separate clamping arrangements greatly increases the labor time expended in finally attaching the tube alignment bars to rigidly support the boiler tubes in a parallel series.
In addition this prior art procedure also permits one to only align three to five of the adjacent tubes normally at one time and accordingly the tube alignment bars are typically manufactured to only clamp three to five tubes at one time in parallel alignment. Thereafter one then must clamp the adjacent three to five tubes in parallel alignment and then apply a second tube alignment bar set and the procedure is carried on until the entire series of boiler tubes is securely clamped in parallel alignment and held in position. Accordingly it can be seen that this procedure for prealigning and preclamping the tubes in addition to applying the tube alignment bars with further clamping means becomes very time consuming.